Accuracy of PCA3 Measurement in Predicting Short-Term Biopsy Progression in an Active Surveillance Program

Transcript Markers from Urinary Extracellular Vesicles for Predicting Risk Reclassification of Prostate Cancer Patients on Active Surveillance

Serum prostate-specific antigen (PSA), its derivatives, and magnetic resonance tomography (MRI) lack sufficient specificity and sensitivity for the prediction of risk reclassification of prostate cancer (PCa) patients on active surveillance (AS). We investigated selected transcripts in urinary extracellular vesicles (uEV) from PCa patients on AS to predict PCa risk reclassification (defined by ISUP 1 with PSA > 10 ng/mL or ISUP 2-5 with any PSA level) in control biopsy. Before the control biopsy, urine samples were prospectively collected from 72 patients, of whom 43% were reclassified during AS. Following RNA isolation from uEV, multiplexed reverse transcription, and pre-amplification, 29 PCa-associated transcripts were quantified by quantitative PCR. The predictive ability of the transcripts to indicate PCa risk reclassification was assessed by receiver operating characteristic (ROC) curve analyses via calculation of the area under the curve (AUC) and was then compared to clinical parameters followed by multivariate regression analysis. ROC curve analyses revealed a predictive potential for AMACR, HPN, MALAT1, PCA3, and PCAT29 (AUC = 0.614-0.655, p < 0.1). PSA, PSA density, PSA velocity, and MRI maxPI-RADS showed AUC values of 0.681-0.747 (p < 0.05), with accuracies for indicating a PCa risk reclassification of 64-68%. A model including AMACR, MALAT1, PCAT29, PSA density, and MRI maxPI-RADS resulted in an AUC of 0.867 (p < 0.001) with a sensitivity, specificity, and accuracy of 87%, 83%, and 85%, respectively, thus surpassing the predictive power of the individual markers. These findings highlight the potential of uEV transcripts in combination with clinical parameters as monitoring markers during the AS of PCa.

Ribonuclease 4 is associated with aggressiveness and progression of prostate cancer

Prostate specific antigen screening has resulted in a decrease in prostate cancer-related deaths. However, it also has led to over-treatment affecting the quality of life of many patients. New biomarkers are needed to distinguish prostate cancer from benign prostate hyperplasia (BPH) and to predict aggressiveness of the disease. Here, we report that ribonuclease 4 (RNASE4) serves as such a biomarker as well as a therapeutic target. RNASE4 protein level in the plasma is elevated in prostate cancer patients and is positively correlated with disease stage, grade, and Gleason score. Plasma RNASE4 level can be used to predict biopsy outcome and to enhance diagnosis accuracy. RNASE4 protein in prostate cancer tissues is enhanced and can differentiate prostate cancer and BPH. RNASE4 stimulates prostate cancer cell proliferation, induces tumor angiogenesis, and activates receptor tyrosine kinase AXL as well as AKT and S6K. An RNASE4-specific monoclonal antibody inhibits the growth of xenograft human prostate cancer cell tumors in athymic mice.

Biomarker in Active Surveillance for Prostate Cancer: A Systematic Review

Active surveillance (AS) in prostate cancer (PCa) represents a curative alternative for men with localised low-risk PCa. Continuous improvement of AS patient's selection and surveillance modalities aims at reducing misclassification, simplifying modalities of surveillance and decreasing need for invasive procedures such repeated biopsies. Biomarkers represent interesting tools to evaluate PCa diagnosis and prognosis, of which many are readily available or under evaluation. The aim of this review is to investigate the biomarker performance for AS selection and patient outcome prediction. Blood, urinary and tissue biomarkers were studied and a brief description of use was proposed along with a summary of major findings. Biomarkers represent promising tools which could be part of a more tailored risk AS strategy aiming to offer personalized medicine and to individualize the treatment and monitoring of each patient. The usefulness of biomarkers has mainly been suggested for AS selection, whereas few studies have investigated their role during the monitoring phase. Randomized prospective studies dealing with imaging are needed as well as larger prospective studies with long-term follow-up and strong oncologic endpoints.

Role of PCA3 and SelectMDx in the optimization of active surveillance in prostate cancer

INTRODUCTION & OBJECTIVES

A not negligible percentage of patients included in active surveillance (AS) for low and very low risk prostate cancer (PCa) are reclassified in the confirmatory biopsy or have disease progression during follow-up. Our aim is to evaluate the role of PCA3 and SelectMDx, in an individual and combined way, in the prediction of pathological progression (PP) in a standard AS program.

MATERIALS & METHODS

Prospective and observational study comprised of 86 patients enrolled in an AS program from 2009 to 2019, with results for PCA3 and SelectMDx previous to PCa diagnosis or during their confirmatory period. Univariate and multivariate analysis were performed to correlate PCA3 and SelectMDx scores as well as clinical and pathological variables with PP-free survival (PPFS). The most reliable cut-offs for both biomarkers in the context of AS were defined.

RESULTS

SelectMDx showed statistically significant differences related to PPFS (HR 1.035, 95%CI: 1.012-1.057) (p = 0.002) with a C-index of 0.670 (95%CI: 0.529-0.810) and AUC of 0.714 (95%CI: 0.603-0.825) at 5 years. In our series, the most reliable cut-off point for SelectMDx was 5, with a sensitivity and specificity for PP of 69.8% and 67.4%, respectively. Same figure for PCA3 was 65, with a sensitivity and specificity for PP of 51.16% and 74.42%, respectively. The combination of both biomarkers did not improve the prediction of PP, C-index 0.630 (95%CI: 0.455-0.805).

CONCLUSIONS

In the context of low or very low risk PCa, SelectMDx > 5 predicted 5 years PP free survival with a moderate discrimination ability outperforming PCA3. The combination of both tests did not improved outcomes.

Role of PCA3 and SelectMDx in the optimization of active surveillance in prostate cancer

INTRODUCTION AND OBJECTIVES

A not negligible percentage of patients included in active surveillance (AS) for low and very low risk prostate cancer (PCa) are reclassified in the confirmatory biopsy or have disease progression during follow-up. Our aim is to evaluate the role of PCA3 and SelectMDx, in an individual and combined way, in the prediction of pathological progression (PP) in a standard AS program.

MATERIALS AND METHODS

Prospective and observational study comprised of 86 patients enrolled in an AS program from 2009 to 2019, with results for PCA3 and SelectMDx previous to PCa diagnosis or during their confirmatory period. Univariate and multivariate analysis were performed to correlate PCA3 and SelectMDx scores as well as clinical and pathological variables with PP-free survival (PPFS). The most reliable cut-offs for both biomarkers in the context of AS were defined.

RESULTS

SelectMDx showed statistically significant differences related to PPFS (HR: 1.035; 95%CI: 1.012-1.057) (P=.002) with a C-index of 0.670 (95%CI: 0.529-0.810) and AUC of 0.714 (95%CI: 0.603-0.825) at 5years. In our series, the most reliable cut-off point for SelectMDx was 5, with a sensitivity and specificity for PP of 69.8% and 67.4%, respectively. Same figure for PCA3 was 65, with a sensitivity and specificity for PP of 51.16% and 74.42%, respectively. The combination of both biomarkers did not improve the prediction of PP, C-index 0.630 (95%CI: 0.455-0.805).

CONCLUSIONS

In the context of low or very low risk PCa, SelectMDx >5 predicted 5years PP free survival with a moderate discrimination ability outperforming PCA3. The combination of both tests did not improved outcomes.

Biomarkers in Prostate Cancer Diagnosis: From Current Knowledge to the Role of Metabolomics and Exosomes

Early detection of prostate cancer (PC) is largely carried out using assessment of prostate-specific antigen (PSA) level; yet it cannot reliably discriminate between benign pathologies and clinically significant forms of PC. To overcome the current limitations of PSA, new urinary and serum biomarkers have been developed in recent years. Although several biomarkers have been explored in various scenarios and patient settings, to date, specific guidelines with a high level of evidence on the use of these markers are lacking. Recent advances in metabolomic, genomics, and proteomics have made new potential biomarkers available. A number of studies focused on the characterization of the specific PC metabolic phenotype using different experimental approaches has been recently reported; yet, to date, research on metabolomic application for PC has focused on a small group of metabolites that have been known to be related to the prostate gland. Exosomes are extracellular vesicles that are secreted from all mammalian cells and virtually detected in all bio-fluids, thus allowing their use as tumor biomarkers. Thanks to a general improvement of the technical equipment to analyze exosomes, we are able to obtain reliable quantitative and qualitative information useful for clinical application. Although some pilot clinical investigations have proposed potential PC biomarkers, data are still preliminary and non-conclusive.

Prostate Health Index and multiparametric magnetic resonance imaging to predict prostate cancer grade reclassification in active surveillance

OBJECTIVE

To identify the value of combining the Prostate Health Index (PHI) and multiparametric magnetic resonance imaging (mpMRI), tools which have previously been shown to be independently predictive of prostate cancer (PCa) grade reclassification (GR; Gleason score >6), for the purpose of predicting GR at the next surveillance biopsy to reduce unnecessary prostate biopsies for men in PCa active surveillance (AS).

PATIENTS AND METHODS

Between 2014 and 2019, we retrospectively identified 253 consecutive men in the Johns Hopkins AS programme who had mpMRI and PHI followed by a systematic ± targeted biopsy. PHI and PHI density (PHID) were evaluated across Prostate Imaging-Reporting and Data System version 2.0 (PI-RADSv2) scores and compared to those with and without GR. Next, the negative predictive value (NPV) and area under the receiver operating curve (AUC) were calculated to compare the diagnostic value of PI-RADSv2 score combined with PHI, PHID, or prostate-specific antigen density (PSAD) for GR using their respective first quartile as a cut-off.

RESULTS

Of the 253 men, 38 men (15%) had GR. Men with GR had higher PHI values (40.7 vs 32.0, P = 0.001), PHID (0.83 vs 0.57, P = 0.007), and PSAD (0.12 vs 0.10, P = 0.037). A PI-RADSv2 ≤3 alone had a NPV of 91.6% for GR (AUC 0.67). Using a PHI cut-off of 25.6 in addition to PI-RADSv2 ≤3, the NPV and AUC were both increased to 98% and 0.70, respectively. Using a PSAD cut-off of 0.07 ng/mL/mL with PI-RADSv2 had an AUC of 0.69 and NPV of 95.4%. PHI and PI-RADSv2 together could have avoided 20% of biopsies at the cost of missing 2.6% of GRs.

CONCLUSIONS

The combination of PHI and mpMRI can aid in the prediction of GR in men on AS and may be useful for decreasing the burden of surveillance prostate biopsies.

Disparities in prostate cancer incidence and mortality rates: Solvable or not?

Prostate cancer (PCa) is recognized as a disease possessing not only great variation in its geographic and racial distribution but also tremendous variation in its potential to cause morbidity and death and it, therefore, ought not to be considered a homogenous disease entity. Morbidity and death from PCa are disproportionately higher in men of African ancestry (MAA) who are generally observed to have more aggressive disease and worse outcomes following treatment compared to men of European ancestry (MEA). The higher rates of PCa among MAA relative to MEA appear to be multifactorial and related to inherent differences in biological aggressiveness; a continued lack of awareness of the disease and methods of prevention; a lower prevalence of screen-detected PCa; comparatively lower access to quality healthcare as well as systemic and institutionalized disparities in the administration of optimal care to MAA in developed countries such as the United States of America where high-quality care is available. Even when access to quality healthcare is assured in equal access settings, it appears that MAA still have worse outcomes after PCa treatment stage-for-stage and grade-for-grade compared to MEA, suggesting that, inherent racial, ethnic and biological differences are paramount in predicting poor outcomes. This review has explored the different contributing factors to the current disparities in PCa incidence and mortality rates with emphasis on the incongruence in how research has been conducted in understanding the disease towards developing therapies.

The long non-coding RNA PCA3: an update of its functions and clinical applications as a biomarker in prostate cancer

Prostate cancer antigen 3 (PCA3) is an overexpressed prostate long non-coding RNA (lncRNA), transcribed from an intronic region at the long arm of human chromosome 9q21–22. It has been described that PCA3 modulates prostate cancer (PCa) cell survival through modulating androgen receptor (AR) signaling, besides controlling the expression of several androgen responsive and cancer-related genes, including epithelial–mesenchymal transition (EMT) markers and those regulating gene expression and cell signaling. Also, PCA3 urine levels have been successfully used as a PCa diagnostic biomarker. In this review, we have highlighted recent findings regarding PCA3, addressing its gene structure, putative applications as a biomarker, a proposed origin of this lncRNA, roles in PCa biology and expression patterns. We also updated data regarding PCA3 interactions with cancer-related miRNAs and expression in other tissues and diseases beyond the prostate. Altogether, literature data indicate aberrant expression and dysregulated activity of PCA3, suggesting PCA3 as a promising relevant target that should be even further evaluated on its applicability for PCa detection and management.

Performance of PCA3 and TMPRSS2:ERG urinary biomarkers in prediction of biopsy outcome in the Canary Prostate Active Surveillance Study (PASS)

BACKGROUND

For men on active surveillance for prostate cancer, biomarkers may improve prediction of reclassification to higher grade or volume cancer. This study examined the association of urinary PCA3 and TMPRSS2:ERG (T2:ERG) with biopsy-based reclassification.

METHODS

Urine was collected at baseline, 6, 12, and 24 months in the multi-institutional Canary Prostate Active Surveillance Study (PASS), and PCA3 and T2:ERG levels were quantitated. Reclassification was an increase in Gleason score or ratio of biopsy cores with cancer to ≥34%. The association of biomarker scores, adjusted for common clinical variables, with short- and long-term reclassification was evaluated. Discriminatory capacity of models with clinical variables alone or with biomarkers was assessed using receiver operating characteristic (ROC) curves and decision curve analysis (DCA).

RESULTS

Seven hundred and eighty-two men contributed 2069 urine specimens. After adjusting for PSA, prostate size, and ratio of biopsy cores with cancer, PCA3 but not T2:ERG was associated with short-term reclassification at the first surveillance biopsy (OR = 1.3; 95% CI 1.0-1.7, p = 0.02). The addition of PCA3 to a model with clinical variables improved area under the curve from 0.743 to 0.753 and increased net benefit minimally. After adjusting for clinical variables, neither marker nor marker kinetics was associated with time to reclassification in subsequent biopsies.

CONCLUSIONS

PCA3 but not T2:ERG was associated with cancer reclassification in the first surveillance biopsy but has negligible improvement over clinical variables alone in ROC or DCA analyses. Neither marker was associated with reclassification in subsequent biopsies.

A novel predictor of clinical progression in patients on active surveillance for prostate cancer

INTRODUCTION

Active surveillance (AS) is standard of care in low-risk prostate cancer (PCa). This study describes a novel total cancer location (TCLo) density metric and aims to determine its performance in predicting clinical progression (CP) and grade progression (GP).

METHODS

This was a retrospective study of patients on AS after confirmatory biopsy (CBx). We excluded patients with Gleason ≥7 at CBx and <2 years followup. TCLo was the number of locations with positive cores at diagnosis (DBx) and CBx. TCLo density was TCLo/prostate volume (PV). CP was progression to any active treatment while GP occurred if Gleason ≥7 was identified on repeat biopsy or surgical pathology. Independent predictors of time to CP or GP were estimated with Cox regression. Kaplan-Meier analysis compared progression-free survival (PFS) curves between TCLo density groups. Test characteristics of TCLo density were explored with receiver operating characteristic (ROC) curves.

RESULTS

We included 181 patients who had CBx from 2012-2015 and met inclusion criteria. The mean age of patients was 62.58 years (standard deviation [SD] 7.13) and median followup was 60.9 months (interquartile range [IQR] 23.4). A high TCLo density score (>0.05) was independently associated with time to CP (hazard ratio [HR] 4.70; 95% confidence interval [CI] 2.62-8.42; p<0.001) and GP (HR 3.85; 95% CI 1.91-7.73; p<0.001). ROC curves showed TCLo density has greater area under the curve than number of positive cores at CBx in predicting progression.

CONCLUSIONS

TCLo density is able to stratify patients on AS for risk of CP and GP. With further validation, it could be added to the decision-making algorithm in AS for low-risk localized PCa.

From biomarkers to therapeutic targets-the promises and perils of long non-coding RNAs in cancer

Biomarker-driven personalized cancer therapy is a field of growing interest, and several molecular tests have been developed to detect biomarkers that predict, e.g., response of cancers to particular therapies. Identification of these molecules and understanding their molecular mechanisms is important for cancer prognosis and the development of therapeutics for late stage diseases. In the past, significant efforts have been placed on the discovery of protein or DNA-based biomarkers while only recently the class of long non-coding RNA (lncRNA) has emerged as a new category of biomarker. The mammalian genome is pervasively transcribed yielding a vast amount of non-protein-coding RNAs including lncRNAs. Hence, these transcripts represent a rich source of information that has the potential to significantly contribute to precision medicine in the future. Importantly, many lncRNAs are differentially expressed in carcinomas and they are emerging as potent regulators of tumor progression and metastasis. Here, we will highlight prime examples of lncRNAs that serve as marker for cancer progression or therapy response and which might represent promising therapeutic targets. Furthermore, we will introduce lncRNA targeting tools and strategies, and we will discuss potential pitfalls in translating these into clinical trials.

Variability in the multicentre National Registry in Active Surveillance; a questionnaire for urologists

BACKGROUND

Our main objective was to report the current use of active surveillance in Spain and to identify areas for potential improvement.

METHODS

A questionnaire generated by the Platform for Multicentre Studies of the Spanish Urology Association (AEU/PIEM/2014/0001, NCT02865330) was sent to all associate researchers from January to March 2016. The questionnaire included 7 domains covering various aspects of active surveillance.

RESULTS

Thirty-three of the 41 associate researchers responded to the questionnaire. Active surveillance is mainly controlled by the urology departments (87.9%). There was considerable heterogeneity in the classical clinical-pathological variables as selection criteria. Only 36.4% of the associate researchers used prostate-specific antigen density (PSAd). Multiparametric magnetic resonance imaging (mpMRI) was clearly underused as initial staging (6%). Only 27.3% of the researchers stated that their radiology colleagues had a high level of experience in mpMRI. In terms of the confirmation biopsy, most of the centres used the transrectal pathway, and only 2 out of 33 used the transperineal pathway or fusion software. Half of the researchers interviewed applied active treatment when faced with disease progression to Gleason 7 (3+4). There was no consensus on when to transition to an observation strategy.

CONCLUSIONS

The study showed the underutilisation of informed consent and quality-of-life questionnaires. PSAd was not included as a decisive element in the initial strategy for most researchers. There was a lack of confidence in the urologists' mpMRI experience and an underutilisation of the transperineal pathway. There was also no consensus on the follow-up protocols and active treatment criteria, confirming the need for prospective studies to analyse the role of mpMRI and biomarkers.

The role of prostate cancer antigen 3 (PCA3) in prostate cancer detection

INTRODUCTION

The prostate cancer antigen 3 (PCA3) score has been the first urine assay to obtain the Food and Drug Administration approval for guiding decisions regarding additional biopsies. Different aspects of this urinary assay (diagnostic performance, prognostic value, cost/benefit balance, integration with other molecular and imaging modalities) have now been well evaluated. Areas covered: This expert review will summarize current achievements and future perspectives provided by this urine biomarker. Expert commentary: The clinical benefit of the PCA3 score, in addition to the other established factors has been demonstrated before regarding biopsy decision making in men with persistent risk of prostate cancer. Its potential prognostic value also suggests its usefulness in selecting low risk patients for active surveillance protocols, however future daily-practice changing studies are needed. Economics assessment and additional value compared with other biomolecular and imaging modalities are still under investigation.

Prostate Biopsy in Active Surveillance Protocols: Immediate Re-biopsy and Timing of Subsequent Biopsies

PURPOSE OF REVIEW

This manuscript reviews contemporary literature regarding prostate cancer active surveillance (AS) protocols as well as other tools that may guide the management of biopsy frequency and assess the possibility of progression in low-risk prostate cancer.

RECENT FINDINGS

There is no consensus regarding the timing of surveillance biopsies; however, an immediate repeat biopsy within 12 months of diagnosis for patients considering AS confirms patients who have favorable risk disease yet also identifies patients who were undersampled initially. Studies regarding multiparametric MRI, nomograms, and biomarkers show promise in risk stratifying and counseling patients during AS. Further studies are needed to determine if these supplemental tests can decrease the frequency of surveillance biopsies. An immediate re-biopsy can help to reduce the risk of missing clinically significant disease. Other clinical tools, including mpMRI, exist that can be used as an adjunct to counsel patients and guide a personalized discussion regarding the frequency of surveillance biopsies.

Biomarkers in active surveillance

The use of active surveillance (AS) is increasing for favorable-risk prostate cancer. However, there remain challenges in patient selection for AS, due to the limitations of current clinical staging. In addition, monitoring protocols relying on serial biopsies is invasive and presents risks such as infection. For these reasons, there is substantial interest in identifying markers that can be used to improve AS selection and monitoring. In this article, we review the evidence on serum, urine and tissue markers in AS.

Whom to Biopsy: Prediagnostic Risk Stratification with Biomarkers, Nomograms, and Risk Calculators

This article describes markers used for prostate biopsy decisions, including prostrate-specific antigen (PSA), free PSA, the prostate health index, 4Kscore, PCA3, and ConfirmMDx. It also summarizes the use of nomograms combining multiple variables for prostate cancer detection.

Prognostic value of urinary prostate cancer antigen 3 (PCA3) during active surveillance of patients with low-risk prostate cancer receiving 5α-reductase inhibitors

OBJECTIVES

To determine the clinical performance of the urinary prostate cancer antigen 3 (PCA3) test to predict the risk of Gleason grade re-classification amongst men receiving a 5α-reductase inhibitor (5ARI) during active surveillance (AS) for prostate cancer.

PATIENTS AND METHODS

Patients with low-risk prostate cancer were enrolled in a prospective Phase II study of AS complemented with prescription of a 5ARI. A repeat biopsy was taken within the first year and annually according to physician and patient preference. In all, 90 patients had urine collected after digital rectal examination of the prostate before the first repeat biopsy. The PCA3 test was performed in a blinded manner at a central laboratory.

RESULTS

Using a PCA3-test score threshold of 35, there was a significant difference (P < 0.001) in the risk of being diagnosed with Gleason ≥7 cancer during a median of 7 years of follow-up. Adjusted Cox regression and Kaplan-Meier analyses also showed a significantly higher risk of upgrading to Gleason ≥7 during follow-up for those with a higher PCA3-test score.

CONCLUSION

The urinary PCA3 test predicted Gleason grade re-classification amongst patients receiving a 5ARI during AS for low-risk prostate cancer.

Preventing clinical progression and need for treatment in patients on active surveillance for prostate cancer

PURPOSE OF REVIEW

Active surveillance is an established treatment option for men with localized, low-risk prostate cancer (CaP). It entails the postponement of immediate therapy with the option of delayed intervention upon disease progression. The rate of clinical progression and need for treatment on active surveillance is approximately 50% over 15 years. The present review summarizes recent data on current methods, attempting to prevent clinical progression.

RECENT FINDINGS

Patient selection for active surveillance is the first mandatory step required to lower progression. Adherence to active surveillance protocols is critical in making sure patients are monitored well and treated early when progression occurs. Before active surveillance allocation and during active surveillance follow-up, methods involving multiparametric MRI, prostate specific antigen derivatives, biopsy factors, urinary, tissue and genetic markers can be used to prevent clinical progression and/or identify those at risk for progression. Medications such as 5α-reductase inhibitors and others might inhibit disease progression in patients on active surveillance.

SUMMARY

Active surveillance is required because of overdiagnosis, along with our inability to accurately predict individual CaP behavior. Several methods can potentially reduce the risk of CaP progression in patients with active surveillance. However, a measure of uncertainty and fear of progression will always accompany patients with active surveillance and the physicians treating them.

Current Management Strategy for Active Surveillance in Prostate Cancer

PURPOSE OF REVIEW

Active surveillance has been increasingly utilized as a strategy for the management of favorable-risk, localized prostate cancer. In this review, we describe contemporary management strategies of active surveillance, with a focus on traditional stratification schemes, new prognostic tools, and patient outcomes.

RECENT FINDINGS

Patient selection, follow-up strategy, and indication for delayed intervention for active surveillance remain centered around PSA, digital rectal exam, and biopsy findings. Novel tools which include imaging, biomarkers, and genetic assays have been investigated as potential prognostic adjuncts; however, their role in active surveillance remains institutionally dependent. Although 30-50% of patients on active surveillance ultimately undergo delayed treatment, the vast majority will remain free of metastasis with a low risk of dying from prostate cancer. The optimal method for patient selection into active surveillance is unknown; however, cancer-specific mortality rates remain excellent. New prognostication tools are promising, and long-term prospective, randomized data regarding their use in active surveillance will be beneficial.

Biomarkers for Prostate Biopsy and Risk Stratification of Newly Diagnosed Prostate Cancer Patients

INTRODUCTION

Many new markers are now available as an aid for decisions about prostate biopsy for men without prostate cancer, and/or to improve risk stratification for men with newly diagnosed prostate cancer.

METHODS

A literature review was performed on currently available markers for use in decisions about prostate biopsy and initial prostate cancer treatment.

RESULTS

Although total prostate-specific antigen cutoffs were traditionally used for biopsy decisions, PSA elevations are not specific. Repeating the PSA test, and adjusting for factors like age, prostate volume and changes over time can increase specificity for biopsy decisions. The Prostate Health Index (phi) and 4K Score are new PSA-based markers that can be offered as second-line tests to decide on initial or repeat prostate biopsy. The PCA3 urine test and ConfirmMDx tissue test are additional options for repeat biopsy decisions. For men with newly diagnosed prostate cancer, genomic tests are available to refine risk classification and may influence treatment decisions.

CONCLUSIONS

Numerous secondary testing options are now available that can be offered to patients deciding whether to undergo prostate biopsy and those with newly diagnosed prostate cancer.

Prognostic Significance of a Negative Confirmatory Biopsy on Reclassification Among Men on Active Surveillance

OBJECTIVE

To examine the association between absence of disease on confirmatory biopsy and risk of pathologic reclassification in men on active surveillance (AS).

MATERIALS AND METHODS

Men with grade groups 1 and 2 disease on AS between 2002 and 2015 were identified who received a confirmatory biopsy within 1 year of diagnosis and ≥3 biopsies overall. The primary outcomes were pathologic reclassification by grade (any increase in primary Gleason pattern or Gleason score) or volume (>33% of sampled cores involved or increase in the number of cores with >50% involvement). The effect of a negative confirmatory biopsy survival was evaluated using Kaplan-Meier analysis and a Cox proportional hazards modeling.

RESULTS

Out of 635 men, 224 met inclusion criteria (median follow-up: 55.8 months). A total of 111 men (49.6%) had a negative confirmatory biopsy. Decreased grade reclassification (69.7% vs 83.9%; P = .01) and volume reclassification (66.3% vs 87.4%; P = .004) was seen at 5 years for men with a negative confirmatory biopsy compared with those with a positive biopsy. On adjusted analysis, a negative confirmatory biopsy was associated with a decreased risk of grade reclassification (hazard ratio, 0.51; 95% confidence interval, 0.28-0.94; P = .03) and volume reclassification (hazard ratio, 0.32; 95% confidence interval, 0.17-0.61; P = .0006) at a median of 4.7 years.

CONCLUSION

Absence of cancer on the confirmatory biopsy is associated with a significant decrease in rate of grade and volume reclassification among men on AS. This information may be used to better counsel men on AS.

Epigenetic Signature: A New Player as Predictor of Clinically Significant Prostate Cancer (PCa) in Patients on Active Surveillance (AS)

Widespread prostate-specific antigen (PSA) testing notably increased the number of prostate cancer (PCa) diagnoses. However, about 30% of these patients have low-risk tumors that are not lethal and remain asymptomatic during their lifetime. Overtreatment of such patients may reduce quality of life and increase healthcare costs. Active surveillance (AS) has become an accepted alternative to immediate treatment in selected men with low-risk PCa. Despite much progress in recent years toward identifying the best candidates for AS in recent years, the greatest risk remains the possibility of misclassification of the cancer or missing a high-risk cancer. This is particularly worrisome in men with a life expectancy of greater than 10–15 years. The Prostate Cancer Research International Active Surveillance (PRIAS) study showed that, in addition to age and PSA at diagnosis, both PSA density (PSA-D) and the number of positive cores at diagnosis (two compared with one) are the strongest predictors for reclassification biopsy or switching to deferred treatment. However, there is still no consensus upon guidelines for placing patients on AS. Each institution has its own protocol for AS that is based on PRIAS criteria. Many different variables have been proposed as tools to enrol patients in AS: PSA-D, the percentage of freePSA, and the extent of cancer on biopsy (number of positive cores or percentage of core involvement). More recently, the Prostate Health Index (PHI), the 4 Kallikrein (4K) score, and other patient factors, such as age, race, and family history, have been investigated as tools able to predict clinically significant PCa. Recently, some reports suggested that epigenetic mapping differs significantly between cancer patients and healthy subjects. These findings indicated as future prospect the use of epigenetic markers to identify PCa patients with low-grade disease, who are likely candidates for AS. This review explores literature data about the potential of epigenetic markers as predictors of clinically significant disease.

The role of prostate cancer biomarkers in undiagnosed men

PURPOSE OF REVIEW

This article intends to review biomarkers derived from blood, urine, and tissue that can aid in the diagnosis of prostate cancer (PCa).

RECENT FINDINGS

PCa screening requires tools that complement prostate-specific antigen (PSA) with a higher specificity for clinically significant disease. Novel blood biomarkers, such as the Prostate Health Index (phi) and 4Kscore, utilize isoforms of PSA to more accurately predict high-grade PCa than traditional tools such as PSA and the percentage free-to-total PSA. Several gene products associated with PCa can be detected in the urine through commercially available assays. PCa antigen 3 (PCA3), though approved for repeat biopsy decisions, appears inferior to other biomarkers such as phi for identifying aggressive disease. However, combinations of PCA3 with other urine assays have shown promising results. One tissue-based hypermethylation test, named ConfirmMDx, can also be used to determine the need for repeat biopsy in men with a prior negative biopsy.

SUMMARY

Several biomarkers have been developed to aid in the screening and diagnosis of PCa. Such tests are often indicated in men with moderately elevated PSA or history of a prior negative biopsy. Their use facilitates reduction of unnecessary biopsies without sacrificing the early diagnosis of clinically significant PCa.

Longitudinal assessment of urinary PCA3 for predicting prostate cancer grade reclassification in favorable-risk men during active surveillance

Background

To assess the utility of urinary prostate cancer antigen 3 (PCA3) as both a one-time and longitudinal measure in men on active surveillance (AS).

Methods

The Johns Hopkins AS program monitors men with favorable-risk prostate cancer with serial PSA, digital rectal examination (DRE), prostate MRI, and prostate biopsy. Since 2007, post-DRE urinary specimens have also been routinely obtained. Men with multiple PCA3 measures obtained over ≥3 years of monitoring were included. Utility of first PCA3 score (fPCA3), subsequent PCA3 (sPCA3), and change in PCA3 were assessed for prediction of Gleason grade reclassification (GR, Gleason score>6) during follow-up.

Results

In total, 260 men met study criteria. Median time from enrollment to fPCA3 was 2 years (IQR 1–3) and from fPCA3 to sPCA3 was 5 years (IQR 4–6). During median follow-up of 6 years (IQR 5–8), 28 men (11%) underwent GR. Men with GR had higher median fPCA3 (48.0vs.24.5, p=0.007) and sPCA3 (63.5vs.36.0, p=0.002) than those without GR, while longitudinal change in PCA3 did not differ by GR status (log-normalized rate 0.07vs.0.06, p=0.53). In a multivariable model including age, risk-classification, and PSA density, fPCA3 remained significantly associated with GR (log[fPCA3] odds ratio=1.77, p=0.04).

Conclusions

PCA3 scores obtained during AS were higher in men who underwent GR, but the rate of change in PCA3 over time did not differ by GR status. PCA3 was a significant predictor of GR in a multivariable model including conventional risk factors, suggesting that PCA3 provides incremental prognostic information in the AS setting.

Beyond prostate-specific antigen: utilizing novel strategies to screen men for prostate cancer

PURPOSE OF REVIEW

The purpose of this article is to review blood and urine tests that are currently available and under investigation for a role in prostate cancer screening and detection.

RECENT FINDINGS

Compared with total prostate-specific antigen (PSA) alone, its combination with percentage free-to-total PSA contributes greater specificity for prostate cancer, and is a component of two newer blood tests called the 4kScore and Prostate Health Index. All three tests improve the prediction of high-grade disease and are commercially available options to aid in initial or repeat prostate biopsy decisions. PCA3 is a urinary marker that is currently available for repeat prostate biopsy decisions. Although PCA3 alone has inferior prediction of clinically significant disease and requires collection of urine after digital rectal examination, it may be combined with other clinical variables or other urine markers like TMPRSS2:ERG to improve performance. Little data are available to support a role for single nucleotide polymorphisms or other investigational markers in early detection.

SUMMARY

Several commercially available blood and urine tests have been shown to improve specificity of PSA for high-grade prostate cancer. Use of such tests would decrease unnecessary biopsy and overdiagnosis of indolent disease. Biopsy of men with moderately elevated PSA without use of such a reflex test should be discouraged.

Active surveillance monitoring: the role of novel biomarkers and imaging

“CANCER” is a disease state that leads to progressive illness that is uniformly fatal without treatment. Hippocrates invoked the Greek word karkinos, or “crab,” to describe tumors he observed. For centuries, “CANCER” remained a disease that was recognized primarily in its locally advanced or metastatic stage, when it was almost uniformly fatal.

Primary Gleason pattern upgrading in contemporary patients with D'Amico low-risk prostate cancer: implications for future biomarkers and imaging modalities

OBJECTIVE

To retrospectively assess the rate of high-grade primary Gleason upgrading (HGPGU) to primary Gleason pattern 4 or 5 in a contemporary cohort of patients with D'Amico low-risk prostate cancer including those who fulfilled Prostate Cancer Research International Active Surveillance (PRIAS) criteria, and to develop a tool for HGPGU prediction. HGPGU is a contraindication in most active surveillance (AS) and focal therapy protocols.

PATIENTS AND METHODS

In all, 10 616 patients with localised prostate cancer were treated at a high-volume European tertiary care centre from 2010 to 2015 with radical prostatectomy. Analyses were restricted to 1 819 patients with D'Amico low-risk prostate cancer (17.1%) with prostate-specific antigen (PSA) levels of <10.0 ng/mL, cT1c-cT2a and Gleason score ≤6, and were repeated within 772 of the men (7.3%) who fulfilled the PRIAS criteria for AS (PSA level of ≤10 ng/mL, T1c-T2, Gleason score ≤6, PSA density (PSAD) of <0.2 ng/mL² , ≤2 positive cores). Uni- and multivariable logistic regression models were fitted, testing predictors of HGPGU. The final logistic regression model was based on the most informative variables.

RESULTS

There was HGPGU in 88 (4.8%) patients with D'Amico low-risk prostate cancer and in 32 (4.1%) of the subgroup who were PRIAS eligible. Multivariable analysis predicting HGPGU for the patients with D'Amico low-risk yielded three independent predictors: age, PSAD, and clinical tumour stage (P = 0.008, P = 0.005 and P = 0.021, respectively). Within the same patients, the model using all vs the most informative variables resulted in area under the curves (AUCs) of 69.2% and 68.3%, respectively. Multivariable analysis of those who were PRIAS eligible, yielded age and number of positive cores as independent predictors of HGPGU (P = 0.002 and P = 0.049, respectively; AUC 64.9%).

CONCLUSIONS

The low accuracy (invariably <70%) for HGPGU prediction in both patients with D'Amico low-risk prostate cancer and PRIAS eligibility indicates that these variables have poor predictive ability in contemporary patients. Despite HGPGU being a rare phenomenon, it may have life threatening implications and consequently alternatives such as biomarkers, genetic markers, or imaging modalities at re-biopsy are needed.

Active surveillance for prostate cancer: current evidence and contemporary state of practice

Prostate cancer remains one of the most commonly diagnosed malignancies worldwide. Early diagnosis and curative treatment seem to improve survival in men with unfavourable-risk cancers, but significant concerns exist regarding the overdiagnosis and overtreatment of men with lower-risk cancers. To this end, active surveillance (AS) has emerged as a primary management strategy in men with favourable-risk disease, and contemporary data suggest that use of AS has increased worldwide. Although published surveillance cohorts differ by protocol, reported rates of metastatic disease and prostate-cancer-specific mortality are exceedingly low in the intermediate term (5-10 years). Such outcomes seem to be closely associated with programme-specific criteria for selection, monitoring, and intervention, suggesting that AS--like other management strategies--could be individualized based on the level of risk acceptable to patients in light of their personal preferences. Additional data are needed to better establish the risks associated with AS and to identify patient-specific characteristics that could modify prognosis.

Active surveillance for prostate cancer: can we modernize contemporary protocols to improve patient selection and outcomes in the focal therapy era?

PURPOSE OF REVIEW

In the absence of whole gland treatment for prostate cancer, both active surveillance and focal therapy share the common need of requiring a more thorough, detailed and precise analysis of the biological threats within the prostatic parenchyma if one chooses to monitor or selectively eradicate only specific neoplastic targets. In addition, focal therapy utilizes active surveillance post-treatment to monitor the untreated sectors of the prostate. We aim to evaluate the current modalities available to modernize active surveillance protocols in order to distinguish patients who may be safely observed from those who require intervention.

RECENT FINDINGS

Traditional active surveillance protocols by today's standards are rudimentary given the rapidly evolving technologies now available to clinicians. There is growing evidence for the adoption and use of multiparametric MRI and MRI-targeted biopsy to identify and localize prostate cancers of higher stage and grade. In addition, serum markers and prostate tissue DNA, RNA and methylation markers provide novel information that extends beyond Gleason grade to better characterize and define prostate cancer prognosis. Current active surveillance protocols should incorporate these modalities to improve patient stratification to surveillance, focal or whole gland interventions.

SUMMARY

Active surveillance protocols should be modernized to include cancer localization modalities and molecular prognostic markers to improve tumour characterization and better stratify men to surveillance, focal or radical intervention.

Risk stratification of prostate cancer in the modern era

PURPOSE OF REVIEW

Novel tools have become available to the practicing urologist in recent years that endeavor to improve on commonly utilized prostate cancer (PCa) risk-stratification techniques. In this review, we provide an overview of these modalities in the context of active surveillance.

RECENT FINDINGS

Multiparametric MRI (MP-MRI) has a rapidly growing body of evidence that suggests it provides the necessary sensitivity and negative predictive value to rule out clinically significant disease. MRI-guided targeted biopsy has the potential to improve detection of clinically significant cancers and for rebiopsy of patients with continued suspicion for PCa. Prostate-specific antigen isoforms and Prostate Health Index outperform PSA alone and improve risk stratification when combined with the established criteria, but need further prospective studies using template and MRI-targeted biopsies. Urinary biomarkers tend to fall short in predicting adverse pathology when used alone, but improve risk stratification when used in conjunction and with the established criteria. Finally, tissue biomarkers and gene assays allow patient-specific molecular and genetic characterization of cancer phenotype, showing significant promise in predicting adverse pathology, and in some cases have already been incorporated into and altered clinical practice.

SUMMARY

These novel modalities show remarkable promise in improving the risk stratification of patients with PCa, and as the body of evidence grows will likely become incorporated into major oncologic guidelines and standard urologic practice. Further prospective clinical studies are needed, as well as analysis of cost-effectiveness.

Biomarkers for prostate cancer: present challenges and future opportunities

Prostate cancer (PCa) has variable biological potential with multiple treatment options. A more personalized approach, therefore, is needed to better define men at higher risk of developing PCa, discriminate indolent from aggressive disease and improve risk stratification after treatment by predicting the likelihood of progression. This may improve clinical decision-making regarding management, improve selection for active surveillance protocols and minimize morbidity from treatment. Discovery of new biomarkers associated with prostate carcinogenesis present an opportunity to provide patients with novel genetic signatures to better understand their risk of developing PCa and help forecast their clinical course. In this review, we examine the current literature evaluating biomarkers in PCa. We also address current limitations and present several ideas for future studies.

Active surveillance for prostate cancer

It is worth distinguishing between the two strategies of expectant management for prostate cancer. Watchful waiting entails administering non-curative androgen deprivation therapy to patients on development of symptomatic progression, whereas active surveillance entails delivering curative treatment on signs of disease progression. The objectives of the two management strategies and the patients enrolled in either are different: (i) to review the role of active surveillance as a management strategy for patients with low-risk prostate cancer; and (ii) review the benefits and pitfalls of active surveillance. We carried out a systematic review of active surveillance for prostate cancer in the literature using the National Center for Biotechnology Information's electronic database, PubMed. We carried out a search in English using the terms: active surveillance, prostate cancer, watchful waiting and conservative management. Selected studies were required to have a comprehensive description of the demographic and disease characteristics of the patients at the time of diagnosis, inclusion criteria for surveillance, and a protocol for the patients' follow up. Review articles were included, but not multiple papers from the same datasets. Active surveillance appears to reduce overtreatment in patients with low-risk prostate cancer without compromising cancer-specific survival at 10 years. Therefore, active surveillance is an option for select patients who want to avoid the side-effects inherent to the different types of immediate treatment. However, inclusion criteria for active surveillance and the most appropriate method of monitoring patients on active surveillance have not yet been standardized.

Potential Utility of Novel Biomarkers in Active Surveillance of Low-Risk Prostate Cancer

Active surveillance (AS) is now an accepted management strategy for men with low-risk localized prostate cancer (PCa). However, detecting disease progression in a patient selected for AS remains a challenge. It is crucial to know what will serve as the best parameter to correctly identify tumors that progress to a more aggressive phenotype so as not to miss the window of curability. Several biomarkers are now being actively investigated as novel tools to improve PCa risk assessments. To date, several serum, urinary, and tissue biomarkers have shown promising prognostic value. %[-2]proPSA and PHI showed improved predictive value for an unfavorable biopsy conversion at annual surveillance biopsy in the AS program. PCA3 and TMPRSS2:ERG had additional independent predictive value for the prediction of PCa detection and progression, although PCA3 was limited in predicting aggressive cancer. Other tissue biomarkers also showed promising ability to predict disease progression. Although several of these novel biomarkers have an improved predictive accuracy that is better than classical parameters, there is still a need for further well-designed, large, multicenter, prospective trials to avoid common bias and clinical validation.

PHI and PCA3 improve the prognostic performance of PRIAS and Epstein criteria in predicting insignificant prostate cancer in men eligible for active surveillance

PURPOSE

To assess the performance of prostate health index (PHI) and prostate cancer antigen 3 (PCA3) when added to the PRIAS or Epstein criteria in predicting the presence of pathologically insignificant prostate cancer (IPCa) in patients who underwent radical prostatectomy (RP) but eligible for active surveillance (AS).

METHODS

An observational retrospective study was performed in 188 PCa patients treated with laparoscopic or robot-assisted RP but eligible for AS according to Epstein or PRIAS criteria. Blood and urinary specimens were collected before initial prostate biopsy for PHI and PCA3 measurements. Multivariate logistic regression analyses and decision curve analysis were carried out to identify predictors of IPCa using the updated ERSPC definition.

RESULTS

At the multivariate analyses, the inclusion of both PCA3 and PHI significantly increased the accuracy of the Epstein multivariate model in predicting IPCa with an increase of 17 % (AUC = 0.77) and of 32 % (AUC = 0.92), respectively. The inclusion of both PCA3 and PHI also increased the predictive accuracy of the PRIAS multivariate model with an increase of 29 % (AUC = 0.87) and of 39 % (AUC = 0.97), respectively. DCA revealed that the multivariable models with the addition of PHI or PCA3 showed a greater net benefit and performed better than the reference models. In a direct comparison, PHI outperformed PCA3 performance resulting in higher net benefit.

CONCLUSIONS

In a same cohort of patients eligible for AS, the addition of PHI and PCA3 to Epstein or PRIAS models improved their prognostic performance. PHI resulted in greater net benefit in predicting IPCa compared to PCA3.

Active surveillance for low-risk prostate cancer

Overtreatment of prostate cancer has become evident as studies comparing radical prostatectomy vs watchful waiting have shown that radical treatment benefits only a proportion of patients. Active surveillance was introduced as a management option for prostate cancer at low-risk of progression with the aim to closely observe for disease progression or change of tumour characteristics and offer active treatment if and when necessary. Active surveillance has been reserved for patients with Gleason 6 localised disease and low PSA; however, selection criteria may be widened as intermediate-term outcomes demonstrate excellent safety, efficacy and patient acceptance.

Expectant management for men with early stage prostate cancer

Since the dissemination of prostate-specific antigen screening, most men with prostate cancer are now diagnosed with localized, low-risk prostate cancer that is unlikely to be lethal. Nevertheless, nearly all of these men undergo primary treatment with surgery or radiation, placing them at risk for longstanding side effects, including erectile dysfunction and impaired urinary function. Active surveillance and other observational strategies (ie, expectant management) have produced excellent long-term disease-specific survival and minimal morbidity for men with prostate cancer. Despite this, expectant management remains underused for men with localized prostate cancer. In this review, various approaches to the expectant management of men with prostate cancer are summarized, including watchful waiting and active surveillance strategies. Contemporary cancer-specific and health care quality-of-life outcomes are described for each of these approaches. Finally, contemporary patterns of use, potential disparities in care, and ongoing research and controversies surrounding expectant management of men with localized prostate cancer are discussed.

Urine TMPRSS2:ERG Plus PCA3 for Individualized Prostate Cancer Risk Assessment

BACKGROUND

TMPRSS2:ERG (T2:ERG) and prostate cancer antigen 3 (PCA3) are the most advanced urine-based prostate cancer (PCa) early detection biomarkers.

OBJECTIVE

Validate logistic regression models, termed Mi-Prostate Score (MiPS), that incorporate serum prostate-specific antigen (PSA; or the multivariate Prostate Cancer Prevention Trial risk calculator version 1.0 [PCPTrc]) and urine T2:ERG and PCA3 scores for predicting PCa and high-grade PCa on biopsy.

DESIGN, SETTING, AND PARTICIPANTS

T2:ERG and PCA3 scores were generated using clinical-grade transcription-mediated amplification assays. Pretrained MiPS models were applied to a validation cohort of whole urine samples prospectively collected after digital rectal examination from 1244 men presenting for biopsy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Area under the curve (AUC) was used to compare the performance of serum PSA (or the PCPTrc) alone and MiPS models. Decision curve analysis (DCA) was used to assess clinical benefit.

RESULTS AND LIMITATIONS

Among informative validation cohort samples (n=1225 [98%], 80% from patients presenting for initial biopsy), models incorporating T2:ERG had significantly greater AUC than PSA (or PCPTrc) for predicting PCa (PSA: 0.693 vs 0.585; PCPTrc: 0.718 vs 0.639; both p<0.001) or high-grade (Gleason score >6) PCa on biopsy (PSA: 0.729 vs 0.651, p<0.001; PCPTrc: 0.754 vs 0.707, p=0.006). MiPS models incorporating T2:ERG score had significantly greater AUC (all p<0.001) than models incorporating only PCA3 plus PSA (or PCPTrc or high-grade cancer PCPTrc [PCPThg]). DCA demonstrated net benefit of the MiPS_PCPTrc (or MiPS_PCPThg) model compared with the PCPTrc (or PCPThg) across relevant threshold probabilities.

CONCLUSIONS

Incorporating urine T2:ERG and PCA3 scores improves the performance of serum PSA (or PCPTrc) for predicting PCa and high-grade PCa on biopsy.

PATIENT SUMMARY

Incorporation of two prostate cancer (PCa)-specific biomarkers (TMPRSS2:ERG and PCA3) measured in the urine improved on serum prostate-specific antigen (or a multivariate risk calculator) for predicting the presence of PCa and high-grade PCa on biopsy. A combined test, Mi-Prostate Score, uses models validated in this study and is clinically available to provide individualized risk estimates.

Prognostic accuracy of Prostate Health Index and urinary Prostate Cancer Antigen 3 in predicting pathologic features after radical prostatectomy

OBJECTIVE

To compare the prognostic accuracy of Prostate Health Index (PHI) and Prostate Cancer Antigen 3 in predicting pathologic features in a cohort of patients who underwent radical prostatectomy (RP) for prostate cancer (PCa).

METHODS AND MATERIALS

We evaluated 156 patients with biopsy-proven, clinically localized PCa who underwent RP between January 2013 and December 2013 at 2 tertiary care institutions. Blood and urinary specimens were collected before initial prostate biopsy for [-2] pro-prostate-specific antigen (PSA), its derivates, and PCA3 measurements. Univariate and multivariate logistic regression analyses were carried out to determine the variables that were potentially predictive of tumor volume > 0.5 ml, pathologic Gleason sum ≥ 7, pathologically confirmed significant PCa, extracapsular extension, and seminal vesicles invasions.

RESULTS

On multivariate analyses and after bootstrapping with 1,000 resampled data, the inclusion of PHI significantly increased the accuracy of a baseline multivariate model, which included patient age, total PSA, free PSA, rate of positive cores, clinical stage, prostate volume, body mass index, and biopsy Gleason score (GS), in predicting the study outcomes. Particularly, to predict tumor volume > 0.5, the addition of PHI to the baseline model significantly increased predictive accuracy by 7.9% (area under the receiver operating characteristics curve [AUC] = 89.3 vs. 97.2, P>0.05), whereas PCA3 did not lead to a significant increase. Although both PHI and PCA3 significantly improved predictive accuracy to predict extracapsular extension compared with the baseline model, achieving independent predictor status (all P's < 0.01), only PHI led to a significant improvement in the prediction of seminal vesicles invasions (AUC = 92.2, P < 0.05 with a gain of 3.6%). In the subset of patients with GS ≤ 6, PHI significantly improved predictive accuracy by 7.6% compared with the baseline model (AUC = 89.7 vs. 97.3) to predict pathologically confirmed significant PCa and by 5.9% compared with the baseline model (AUC = 83.1 vs. 89.0) to predict pathologic GS ≥ 7. For these outcomes, PCA3 did not add incremental predictive value.

CONCLUSIONS

In a cohort of patients who underwent RP, PHI is significantly better than PCA3 in the ability to predict the presence of both more aggressive and extended PCa.

Circulating biomarkers for discriminating indolent from aggressive disease in prostate cancer active surveillance

PURPOSE OF REVIEW

To review research on the use of circulating biomarkers to predict unfavorable tumor pathology in the setting of active surveillance, or in clinical contexts that are informative for active surveillance, such as men with low-risk prostate cancer evaluated for upgrading or upstaging at surgery.

RECENT FINDINGS

Biomarkers have been evaluated in serum, plasma, urine, and expressed prostatic secretions. Only a small number of biomarkers have been evaluated in multiple studies: %free prostate-specific antigen (PSA), PSA velocity, PSA doubling time, proPSA, PCA3, TMPRSS2-ERG. Single studies with relevance to active surveillance have evaluated microRNAs, circulating tumor cells, and exosomes. The most consistent significant associations with unfavorable tumor pathology have been with %free PSA. Associations with [-2]proPSA and Prostate Health Index have also been consistent; however, three of four studies come from the same active surveillance patient cohort.

SUMMARY

Circulating biomarkers represent a promising approach to identify men with apparently low-risk biopsy pathology, but who harbor potentially aggressive tumors unsuitable for active surveillance. Research is still at an early stage; existing biomarkers need rigorous validation with consistent methodology, and additional biomarkers need to be evaluated. Successful clinical translation would reduce the frequency of surveillance biopsies, and may enhance acceptance of active surveillance.

The prostate health index selectively identifies clinically significant prostate cancer

PURPOSE

The Prostate Health Index (phi) is a new test combining total, free and [-2]proPSA into a single score. It was recently approved by the FDA and is now commercially available in the U.S., Europe and Australia. We investigate whether phi improves specificity for detecting clinically significant prostate cancer and can help reduce prostate cancer over diagnosis.

MATERIALS AND METHODS

From a multicenter prospective trial we identified 658 men age 50 years or older with prostate specific antigen 4 to 10 ng/ml and normal digital rectal examination who underwent prostate biopsy. In this population we compared the performance of prostate specific antigen, % free prostate specific antigen, [-2]proPSA and phi to predict biopsy results and, specifically, the presence of clinically significant prostate cancer using multiple criteria.

RESULTS

The Prostate Health Index was significantly higher in men with Gleason 7 or greater and "Epstein significant" cancer. On receiver operating characteristic analysis phi had the highest AUC for overall prostate cancer (AUCs phi 0.708, percent free prostate specific antigen 0.648, [-2]proPSA 0.550 and prostate specific antigen 0.516), Gleason 7 or greater (AUCs phi 0.707, percent free prostate specific antigen 0.661, [-2]proPSA 0.558, prostate specific antigen 0.551) and significant prostate cancer (AUCs phi 0.698, percent free prostate specific antigen 0.654, [-2]proPSA 0.550, prostate specific antigen 0.549). At the 90% sensitivity cut point for phi (a score less than 28.6) 30.1% of patients could have been spared an unnecessary biopsy for benign disease or insignificant prostate cancer compared to 21.7% using percent free prostate specific antigen.

CONCLUSIONS

The new phi test outperforms its individual components of total, free and [-2]proPSA for the identification of clinically significant prostate cancer. Phi may be useful as part of a multivariable approach to reduce prostate biopsies and over diagnosis.

Active surveillance for prostate cancer: a systematic review of clinicopathologic variables and biomarkers for risk stratification

CONTEXT

Active surveillance (AS) is an important strategy to reduce prostate cancer overtreatment. However, the optimal criteria for eligibility and predictors of progression while on AS are debated.

OBJECTIVE

To review primary data on markers, genetic factors, and risk stratification for patient selection and predictors of progression during AS.

EVIDENCE ACQUISITION

Electronic searches were conducted in PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to April 2014 for original articles on biomarkers and risk stratification for AS.

EVIDENCE SYNTHESIS

Patient factors associated with AS outcomes in some studies include age, race, and family history. Multiple studies provide consistent evidence that a lower percentage of free prostate-specific antigen (PSA), a higher Prostate Health Index (PHI), a higher PSA density (PSAD), and greater biopsy core involvement at baseline predict a greater risk of progression. During follow-up, serial measurements of PHI and PSAD, as well as repeat biopsy results, predict later biopsy progression. While some studies have suggested a univariate relationship between urinary prostate cancer antigen 3 (PCA3) and transmembrane protease, serine 2-v-ets avian erythroblastosis virus E26 oncogene homolog gene fusion (TMPRSS2:ERG) with adverse biopsy features, these markers have not been consistently shown to independently predict AS outcomes. No conclusive data support the use of genetic tests in AS. Limitations of these studies include heterogeneous definitions of progression and limited follow-up.

CONCLUSIONS

There is a growing body of literature on patient characteristics, biopsy features, and biomarkers with potential utility in AS. More data are needed on practical applications such as combining these tests into multivariable clinical algorithms and long-term outcomes to further improve AS in the future.

PATIENT SUMMARY

Several PSA-based tests (free PSA, PHI, PSAD) and the extent of cancer on biopsy can help to stratify the risk of progression during active surveillance. Investigation of several other markers is under way.

Indications for intervention during active surveillance of prostate cancer: a comparison of the Johns Hopkins and Prostate Cancer Research International Active Surveillance (PRIAS) protocols

OBJECTIVE

To analyse how patients enrolled in our biopsy based surveillance programme would fare under the Prostate Cancer Research International Active Surveillance (PRIAS) protocol, which uses PSA kinetics.

PATIENTS AND METHODS

Since 1995, 1125 men with very-low-risk prostate cancer have enrolled in the AS programme at the Johns Hopkins Hospital (JHH), which is based on monitoring with annual biopsy. The PRIAS protocol uses a combination of periodic biopsies (in years 1, 4, and 7) and prostate-specific antigen doubling time (PSADT) to trigger intervention. Patients enrolled in the JHH AS programme were retrospectively reviewed to evaluate how the use of the PRIAS protocol would alter the timing and use of curative intervention.

RESULTS

Over a median of 2.1 years of follow up, 38% of men in the JHH AS programme had biopsy reclassification. Of those, 62% were detected at biopsy intervals corresponding to the PRIAS criteria, while 16% were detected between scheduled PRIAS biopsies, resulting in a median delay in detection of 1.9 years. Of the 202 men with >5 years of follow-up, 11% in the JHH programme were found to have biopsy reclassification after it would have been identified in the PRIAS protocol, resulting in a median delay of 4.7 years to reclassification. In all, 12% of patients who would have undergone immediate intervention under PRIAS due to abnormal PSA kinetics would never have undergone reclassification on the JHH protocol and thus would not have undergone definitive intervention.

CONCLUSIONS

There are clear differences between PSA kinetics-based AS programmes and biopsy based programmes. Further studies should address whether and how the differences in timing of intervention impact subsequent disease progression and prostate cancer mortality.

Seventh Joint Meeting of K-J-CaP and CaPSURE: extending the global initiative to improve prostate cancer management

This report summarizes the presentations and discussions that took place at the Seventh Joint Meeting of the Korea–Japan Study Group of Prostate Cancer (K-J-CaP) and the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) held in Seoul, Korea, in September 2013. The original J-CaP and CaPSURE Joint Initiative has now been established since 2007 and since the initial collaboration between research teams in the United States (US) and Japan, the project has expanded to include several other Asian countries. The objective of the initiative is to analyze and compare data for prostate cancer patients in the participating countries, looking at similarities and differences in patient management and outcomes. Until now the focus has been primarily on data generated within J-CaP and CaPSURE, both large-scale, longitudinal, observational databases of prostate cancer patients in Japan and the US, respectively. This year’s meeting was hosted for the first time in Korea which has recently established its own national database–K-CaP–to add to the wealth of data generated by J-CaP and CaPSURE. As a newly-developed database, K-CaP has also provided a valuable ‘template’ for other countries, such as China and Indonesia, planning to establish their own national databases and this will ultimately allow greater opportunities for international data comparisons. A range of topics was discussed at this Seventh Joint Meeting including comparison of outcomes following androgen deprivation therapy or radical prostatectomy in patients with localized prostate cancer, the use of active surveillance as a treatment option and the triggers for intervention when employing this regimen, patient quality of life during treatment, the impact of comorbidities on outcomes, and a comparison of recent outcomes data between J-CaP and CaPSURE. The participants recognized that prostate cancer was now a global disease and therefore major insights into understanding and improving the management of this condition would arise from global interactions such as this joint initiative.

The Prostate Health Index: a new test for the detection of prostate cancer

A major focus in urologic research is the identification of new biomarkers with improved specificity for clinically-significant prostate cancer. A promising new test based on prostate-specific antigen (PSA) is called the Prostate Health Index (PHI), which has recently been approved in the United States, Europe and Australia. PHI is a mathematical formula that combines total PSA, free PSA and [-2] proPSA. Numerous international studies have consistently shown that PHI outperforms its individual components for the prediction of overall and high-grade prostate cancer on biopsy. PHI also predicts the likelihood of progression during active surveillance, providing another noninvasive modality to potentially select and monitor this patient population. This article reviews the evidence on this new blood test with significant promise for both prostate cancer screening and treatment decision-making.

Risk-based prostate cancer screening: who and how?

The purpose of this review is to identify clinical risk factors for prostate cancer and to assess the utility and limitations of our current tools for prostate cancer screening. Prostate-specific antigen is the single most important factor for identifying men at increased risk of prostate cancer but is best assessed in the context of other clinical factors; increasing age, race, and family history are well-established risk factors for the diagnosis of prostate cancer. In addition to clinical risk calculators, novel tools such as multiparametric imaging, serum or urinary biomarkers, and genetic profiling show promise in improving prostate cancer diagnosis and characterization. Optimal use of existing and future tools will help alleviate the problems of overdiagnosis and overtreatment of low-risk prostate cancer without reversing the substantial mortality declines that have been achieved in the screening era.